Mold assembly and method of molding a component

ABSTRACT

A mold assembly includes a first upper portion, a second upper portion, and a base removably coupled to each other. A method of manufacturing an electrical connector with the mold assembly includes preheating a resin, mixing the resin with a hardener, preheating the mold assembly, injecting the resin hardener mixture into the mold assembly, and curing the resin hardener mixture.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims priority to U.S.Non-Provisional application Ser. No. 14/984,080, filed on Dec. 30, 2015and titled “A MOLD ASSEMBLY AND METHOD OF MOLDING A COMPONENT,” thedisclosure of which is expressly incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention described herein includes contributions by one or moreemployees of the Department of the Navy made in performance of officialduties and may be manufactured, used and licensed by or for the UnitedStates Government for any governmental purpose without payment of anyroyalties thereon. This invention (Navy Case 200,521) is assigned to theUnited States Government and is available for licensing for commercialpurposes. Licensing and technical inquiries may be directed to theTechnology Transfer Office, Naval Surface Warfare Center Crane, email:Cran_CTO@navy.mil.

FIELD OF THE DISCLOSURE

The present invention relates generally to a mold assembly and a methodof molding a component and, in particular, to a mold assembly and amethod of manufacturing an electrical component with the mold assembly.

BACKGROUND OF THE DISCLOSURE

Various components may be used for underwater applications. If thecomponent is an electrical component, the component should be completelycured such that the component is waterproof to electrical shorting ordamage to the electrical component from contact with water. A pluralityof materials and processes may be used to mold various components forunderwater electrical applications.

In one illustrative embodiment, electrical components may be made fromvarious resins injected into closed molds, for example through injectionmolding. However, injection molding certain materials to form electricalcomponents may result in an electrical component with increased airvoids due to an increase in the resin viscosity during injectionmolding. Additionally, injection molded components may require a longer(for example, 24-hour) cure time, which decreases the ability to makelarge quantities of electrical components in a limited period of time.Furthermore, various electrical components formed through injectionmolding processes may be brittle, thereby increasing the likelihood offailure or breakage of the component.

SUMMARY OF THE DISCLOSURE

However, certain materials such as epoxy resins, may be molded throughvarious processes which result in a shorter cure time and decreasedbrittleness of the electrical component. In one embodiment, ChockfastOrange® is an epoxy resin developed by ITW Engineered Polymers ofMontgomeryville, Pa., which may be used to mold various electricalcomponents, such as electrical connectors, for underwater applications.In one embodiment, Chockfast Orange® may be poured into an open mold atroom temperature with a 20:1 mixed ratio of resin to hardener and curedat a room temperature for less than approximately 24 hours.

In one illustrative embodiment of the present disclosure, a method ofmanufacturing an electrical connector includes preheating a resincomposition, mixing the resin composition with a hardener to form aresin-hardener mixture, preheating a mold assembly, injecting theresin-hardener mixture into the mold assembly, and curing the mixturefor less than 24 hours.

In another illustrative embodiment of the present disclosure, a methodof manufacturing an electrical connector includes preheating a resincomposition for up to 30 minutes at a temperature between 100° F. and150° F., mixing the resin composition with a hardener to form aresin-hardener mixture at a resin to hardener ratio between 12:1 and25:1, preheating a mold assembly to a temperature between 75° F. and125° F. for at least 30 minutes, injecting the resin-hardener mixtureinto the mold assembly at a pressure of 1-8 psig, and curing the mixturefor less than 24 hours.

In a further illustrative embodiment of the present disclosure, a moldassembly includes a first upper portion, a second upper portion, and abase. The base, the first upper portion, and the second upper portionare each removably coupled to each other, and the configuration of thefirst upper portion, the second upper portion, and the base creates achannel that extends along a length of the base to accommodate aplurality of wires within the channel. The first upper portion and thesecond upper portion each have a bottom surface wherein the bottomsurface of the second upper portion is closer to a bottom surface of thebase than the bottom surface of the first upper portion. Additionally, alocator plate is removably coupled to the first upper portion, thesecond upper portion, and the base.

In another illustrative embodiment of the present disclosure, anassembly comprises a mold assembly and a cable configured to bepositioned within the mold assembly. The cable includes a plurality ofwires. The assembly also comprises a clamp removably coupled to aportion of the cable extending from the mold assembly and a storage unitfor supporting a portion of the cable. The clamp is positionedintermediate the storage unit and the mold assembly.

In a further illustrative embodiment of the present disclosure, anassembly comprises a storage unit and a cable containing a plurality ofwires. The cable is supported by the storage unit. The assembly alsocomprises a workbench including a workbench track and a workbench trackrests on the workbench. The cable is positioned within the workbenchtrack. The assembly also comprises a clamp removably coupled to thecable and a mold assembly configured to receive the cable. The moldassembly includes a first upper portion, a second upper portion, and abase, wherein the base, the first upper portion, and the second upperportion are each removably coupled to each other. The configuration ofthe first upper portion, the second upper portion, and the base createsa channel that extends along a length of the base to accommodate thecable within the channel. The base includes a bottom surface, a firsttop surface, and a second top surface such that the first top surface isat a greater distance from the bottom surface of the base than thesecond top surface. The first upper portion and the second upper portioneach have a bottom surface, wherein the bottom surface of the secondupper portion is closer to the bottom surface of the base than thebottom surface of the first upper portion. The mold assembly alsoincludes a locator plate removably coupled to the first upper portion,the second upper portion, and the base, wherein the locator plateincludes a plurality of holes each configured to receive one of aplurality of pins includes on the plurality of wires of the cable.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features of this invention, and the mannerof attaining them, will become more apparent and the invention itselfwill be better understood by reference to the following description ofembodiments of the invention taken in conjunction with the accompanyingdrawings, where:

FIG. 1 is a front perspective view of an illustrative mold assembly inaccordance with the present disclosure;

FIG. 2 is a rear perspective view of an underside of the mold assemblyof FIG. 1;

FIG. 3 is an exploded perspective view of the mold assembly of FIG. 1;

FIG. 4 is a cross-sectional view of the mold assembly of FIG. 1, takenalong line 4-4 of FIG. 1;

FIG. 5 is a front perspective view of an electrical connector cableformed with an electrical connector within the mold assembly of FIG. 1;

FIG. 6 is a perspective view of a plurality of mold assemblies forforming the electrical connector cable of FIG. 5; and

FIG. 7 is a flow chart of an illustrative method of manufacturing theelectrical connector cable of FIG. 5 according to the mold assembly ofFIG. 6.

Corresponding reference characters indicate corresponding partsthroughout the several views. Unless stated otherwise the drawings areproportional.

DETAILED DESCRIPTION OF THE DRAWINGS

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, which are described below. The embodimentsdisclosed below are not intended to be exhaustive or limit the inventionto the precise form disclosed in the following detailed description.Rather, the embodiments are chosen and described so that others skilledin the art may utilize their teachings. Therefore, no limitation of thescope of the claimed invention is thereby intended. The presentinvention includes any alterations and further modifications of theillustrated devices and described methods and further applications ofthe principles of the invention which would normally occur to oneskilled in the art to which the invention relates.

Referring to FIGS. 1-4, an illustrative embodiment of a mold assembly 1is shown. Mold assembly 1 includes a first upper portion 3, a secondupper portion 5, and a base 7 removably coupled to each other by atleast one fastener 15, illustratively a plurality of screws, and atleast one coupler 21, illustratively a plurality of dowel pins (FIG. 3).When first upper portion 3, second upper portion 5, and base 7 arecoupled to each other, a plurality of processing ports 14 are defined atthe interface between first upper portion 3 and second upper portion 5and at the interface between at least second upper portion 6 and base 7,as shown in FIG. 1. When first and second upper portions 3, 5 arecoupled together, at least one, and illustratively three upperprocessing ports 14 are defined there between, as shown in FIGS. 1 and4. Upper processing ports 14 a are configured to operate as air ventsand/or material overflow ports for mold assembly 1. Additionally, alower processing port 14 b is defined at the interface of at leastsecond upper portion 5 and base 7. Lower processing port 14 b defines aninjection port into which a material may be injected during a moldingprocess, as disclosed further herein. Illustratively, first and secondupper portions 3, 5 each includes a bottom surface 4, 6 which abuts topsurfaces 8, 10 of base 7, respectively, as disclosed herein. Base 7 alsoincludes a bottom surface 12 opposing top surfaces 8, 10.

In one embodiment, first upper portion 3 and second upper portion 5 aremirror-image components of each other. Alternatively, as shown in FIGS.2 and 3, first and second upper portions 3, 5 are not identicalcomponents of mold assembly 1 in that second upper portion 5 has alarger size than first upper portion 3. For example, bottom surface 6 ofsecond upper portion 5 has a vertical length or height h₂ greater than avertical length or height h₁ of first upper portion 3 such that bottomsurface 6 of second upper portion 5 is closer to bottom surface 12 ofbase 7 than is bottom surface 4 of first upper portion 3. As a result,first upper portion 3 and second upper portion 5 are not identical partsprimarily due to the differences in height.

To accommodate the different sizes of first and second upper portions 3,5, base 7 has first top surface 8 and second top surface 10, as shown inFIG. 3. First top surface 8 abuts bottom surface 4 of first upperportion 3 when first upper portion 3 is coupled to base 7. Second topsurface 10 abuts bottom surface 6 of second upper portion 5 when secondupper portion 5 is coupled to base 7. In the present embodiment, firsttop surface 8 has a greater vertical distance or height h₃ from bottomsurface 12 of base 7 than the vertical distance or height h₄ from secondtop surface 10 to bottom surface 12, to accommodate the difference inheight between first upper portion 3 and second upper portion 5. In analternative embodiment, first top surface 8 and second top surface 10 ofbase 7 do not vary in height with respect to bottom surface 12 of base7.

Referring to FIG. 2, a rear end 2 b of mold assembly 1 is shown andincludes a channel 23. Channel 23 is defined by the inward facingsurfaces of first upper portion 3, second upper portion 5, and base 7when first upper portion 3, second upper portion 5, and base 7 arecoupled to one another. Channel 23 spans a length L of mold assembly 1(FIG. 4). In one exemplary embodiment, length L corresponds to a lengthof base 7. In an alternative embodiment, length L corresponds with alength of either first upper portion 3 or second upper portion 5.Channel 23 is configured to receive at least one wire or cable 25, asdisclosed herein.

Referring to FIGS. 1, 3, and 4, at a front end 2 a of mold assembly 1, alocator plate 9 of mold assembly 1 is removably coupled to first upperportion 3, second upper portion 5, and base 7 by at least one fastener16, illustratively a plurality of screws. Locator plate 9 includes aplurality of holes 11 which open to channel 23 and are configured toreceive individual connector pins of electrical wires, as disclosedfurther herein. For example, in one embodiment, holes 11 of locatorplate 9 each are configured to receive one of a plurality of connectorpins 27 a of each electrical wire 27 of cable 25 (FIG. 5). Holes 11 arespaced apart from one another such that there is sufficient space foreach pin 27 a of each wire 27 to engage with hole 11 without interferingwith another pin 27 a. Also, holes 11 extend axially from locator plate9 and away from front end 2 a of mold assembly 1. As such, locator plate9 provides a relative placement of each pin 27 a spatially orientedrelative to each other and also axially positions each pin 27 a. Eachhole 11 also may include a sleeve 17 removably inserted therein andconfigured to receive each pin 27 a or any other wire, cable, pin, orother electrical component, as shown in FIG. 3. Additionally, an insert19 is removably coupled to mold assembly 1 and is inserted at theinterface of bottom surface 4 of first upper portion 3 and top surface 8of base 7 (FIG. 3). Insert 19 facilitates the assembly and disassemblyof mold assembly 1.

Referring still to FIGS. 1-4, in one embodiment, a heating plate 13 isremovably coupled to mold assembly 1 and, more particularly, to a bottomsurface 12 of base 7 by at least one fastener 18, illustratively aplurality of screws (FIGS. 2-3). In an exemplary embodiment, heatingplate 13 is electrically coupled to a power source (not shown) by atleast one cable 30 (FIG. 6) where the power source enables heating plate13 to increase the temperature of base 7.

By having mold assembly 1 comprise multiple discrete parts—first upperportion 3, second upper portion 5, base 7, and locator plate 9—moldassembly 1 is easily disassembled and/or reassembled as needed.Additionally, the configuration of heights h1, h2, h3, h4 of first upperportion 3, second upper portion 5, and base 7 allow for easy assemblyand disassembly of mold assembly 1 and facilitates removal of acomponent formed therein. More particularly, if a component is formedwithin mold assembly 1, the component is easily removed from moldassembly 1 without damage thereto by removing fasteners 15, 16, 18 andcouplers 21 from mold assembly 1. Alternatively, couplers 21 may bepressed fit and remain within mold assembly 1 during disassembly of moldassembly 1. Also, improved cleaning of mold assembly 1 can be achievedas each individual part can be cleaned separately.

Referring to FIGS. 5 and 6, a cable 25 is configured to be positionedwithin channel 23 at rear end 2 b of mold assembly 1 to form anelectrical connector 100 at a distal end 26 of cable 25. Cable 25encloses a plurality of electrical wires or lines 27 which extendthrough distal end 26 and terminate in a pin 27 a. Electrical connector100 is positioned intermediate distal end 26 and pins 27 a and iscomprised of a polymeric material. For example, electrical connector 100may be comprised of 100% solids, two component inert compounds comprisedof a resin and a hardener. More particularly, the material may includebetween 30% and 60% concentration of a crystalline silica, between 30%and 60% concentration of an epoxy resin, and between 5% and 15%concentration of a limestone, where the epoxy resin is a reactionproduct of bisphenol A and epichlorohydrin. In one embodiment,electrical connector 100 is comprised of Chockfast Orange®.

Referring to FIGS. 4-7, to form electrical connector 100, first andsecond upper portions 3, 5 are removed from base 7 and all portions ofmold assembly 1 are cleaned, including the interior surfaces of firstupper portion 3, second upper portion 5, and base 7, as shown in Step101 of FIG. 7. For example, mold assembly 1 may be cleaned with alcoholand a lint-free cloth.

Before positioning anything in mold assembly 1, a mold release agent maybe applied to the interior surfaces thereof to easily release anycomponents from mold assembly 1, as shown in Step 102 of FIG. 7. Oncethe mold release agent is applied, the components of mold assembly 1 dryfor approximately 3-10 minutes and, more particularly, for approximately5 minutes, as shown in Step 103 of FIG. 7. Additional applications ofthe mold release agent may be applied 1-5 more times with periods ofdrying in between. In one exemplary embodiment, the mold release agentis Freekote CUR available from Henkel Corporation.

Once mold assembly 1 is prepared, mold assembly 1 may be heated withheating plate 13, as shown in Step 104 of FIG. 7. For example, moldassembly 1 may be heated for up to 60 minutes and, more particularly,approximately 15-45 minutes and, even more particularly, approximately20-30 minutes at a temperature of 75-125° F. and, more particularly,approximately 100° F.

Referring to Step 105 of FIG. 7, distal end 26 of cable 25 is placedwithin a first portion 23 a of channel 23 of mold assembly 1 and eachwire extends through channel 23 over length L towards locator plate 9.Each pin 27 a of each wire 27 is received within a corresponding sleeve17 and hole 11 of locator plate 9. Sleeves 17 are placed over pins 27 ato further protect pins 27 a from potential damage during the moldingprocess. Additionally, by positioning pins 27 a within sleeves 17 andholes 11, the wires are held in place when a resin composition is addedto channel 23 of mold assembly 1 to form electrical connector 100.

Mold assembly 1 is then assembled around cable 25 such that first andsecond upper portions 3, 5 are coupled to base 7 and locator plate 9, asshown in Step 106 of FIG. 7. With cable 25 positioned within moldassembly 1, the material comprising electrical connector 100 isprepared. More particularly, and using Chockfast Orange® as anillustrative embodiment of the material comprising electrical connector100, as shown in Step 107, a measured quantity of the resin component ofChockfast Orange® is heated, for example in an oven, for less than 60minutes and, more particularly, for 20-30 minutes, at a temperature of100-150° F. and, more particularly, at 125-135° F.

After heating the resin component, the resin is mixed with the hardenerto form Chockfast Orange®, as shown in Step 108 of FIG. 7. In oneembodiment, the resin is mixed with the hardener in a 12:1 to 25:1 ratioof resin to hardener. Illustratively, electrical connector 100 iscomprised of Chockfast Orange® with a 20:1 ratio of resin to hardener.The resin-hardener ratio enables the mixture to be molded at elevatedtemperatures without producing a brittle component in mold assembly 1.The resin-hardener mixture is stirred slowly to prevent pockets of airfrom forming in the mixture. Stirring is done until the resin andhardener are uniformly mixed up to approximately 1-5 minutes of mixingand, more particularly, approximately 2 minutes of mixing. Afterstirring, the resin-hardener mixture is degassed in a vacuum chamber for1 minute, as shown in Step 109 of FIG. 7.

In Step 110 of FIG. 7, the resin-hardener mixture is injected into asecond portion 23 b (FIG. 4) of mold assembly 1 under pressure throughlower processing port 14 h (FIG. 1) until mold assembly 1 is filled tocapacity with the mixture. In the present embodiment, the pressure maybe as little as about 1-8 psig and, more particularly 3-4 psig.Additionally, the resin-hardener mixture is injected into a thirdportion 23 c of channel 23 through lower processing port 14 h toencompass a portion of pins 27 a of cable 25. Due to the configurationof third portion 23 a, an o-ring groove 29 may be molded into electricalconnector 100 such that an o-ring (not shown) may be included onelectrical connector 100 to sealingly secure electrical connector 100 toanother electrical component.

Once mold assembly 1 is filled with the resin-hardener mixture, theresin-hardener mixture is cured for less than 24 hours in Step 111 ofFIG. 7. More particularly, the curing process of Step 111 may beapproximately one hour in which for approximately 30 minutes, heatingplate 13 is turned off such that no additional heating to mold assembly1 occurs. Subsequently, heating plate 13 may be turned back on toincrease the temperature of mold assembly 1 to 115-150° F. and, moreparticularly, to approximately 140° F. for the remaining 30 minutes ofthe I-hour cure cycle.

As shown in Step 112 of FIG. 7, after Step 111 is completed, heatingplate 13 is turned off and mold assembly 1 is allowed to cool for 1-15minutes and, more particularly, 5 minutes. After the cooling cycle, atStep 113 of FIG. 7, mold assembly 1 is disassembled to remove firstupper portion 3 and second upper portion 5 from base 7. With first andsecond upper portions 3, 5 removed, electrical connector 100 ispositioned on base 7, as shown in FIG. 6. In this way, electricalconnector 100 is positioned around a portion of the wires comprisingcable 25 and is coupled to cable 25. As shown in FIG. 5, pins 27 a ofcable 25 extend from electrical connector 100 such that pins 27 a may beelectrically coupled to another component (not shown). Once cooled,cable 25, including electrical connector 100, may be removed from moldassembly 1 and electrically coupled with any other electrical componentor system, depending on the application of cable 25.

In one embodiment, multiple mold assemblies 1 may be used tosimultaneously form a plurality of electrical connectors 100, as shownin FIG. 6. For example, a plurality of bases 7 and heating plates 13 maybe coupled to a workbench 503 and a workbench track 502 such that base 7and heating plate 13 are stationary with respect to workbench 503 andworkbench track 502.

Cable 25 may be positioned within workbench track 502 and may extendfrom mold assembly 1 to a clamp 501 and a storage unit 505, which areconfigured upstream of mold assembly 1. Clamp 501 may be removablycoupled to cable 25 to further secure the alignment of distal end 26 ofcable 25 within channel 23 of mold assembly 1 by preventing rotationalor axial movement of cable 25. By limiting movement of cable 25, thepositioning of pins 27 a within holes 11 of locator plate 9 remains setand secure. In an exemplary embodiment, storage unit 505 may comprise ofrolls, spools, or drums on which the remaining length of cable 25 iswound.

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

What is claimed is:
 1. A mold assembly comprising: a first upperportion, a second upper portion, and a base, wherein the base, the firstupper portion, and the second upper portion are each removably coupledto each other and the configuration of the first upper portion, thesecond upper portion, and the base creates a channel that extends alonga length of the base to accommodate a plurality of wires within thechannel; the first upper portion and the second upper portion eachhaving a bottom surface, wherein the bottom surface of the second upperportion is closer to a bottom surface of the base than the bottomsurface of the first upper portion; and a locator plate removablycoupled to the first upper portion, the second upper portion, and thebase.
 2. The mold assembly of claim 1, wherein the locator plateincludes a plurality of holes wherein each of the holes corresponds to awire configured to extend through one of the plurality of holes of thelocator plate.
 3. The mold assembly of claim 1, wherein the base furtherincludes a first top surface and a second top surface such that thefirst top surface is at a greater distance from the bottom surface ofthe base than the second top surface.
 4. The mold assembly of claim 1,wherein a cable containing a plurality of wires is positioned oppositeof the locator plate and within the channel such that the plurality ofwires extends through the channel and the plurality of wires extendstowards the locator plate.
 5. The mold assembly of claim 4, furthercomprising a storage unit and a clamp, wherein the cable extends fromthe mold assembly to the clamp and the storage unit.
 6. An assemblycomprising: a mold assembly; a cable configured to be positioned withinthe mold assembly and including a plurality of wires; a clamp removablycoupled to a portion of the cable extending from the mold assembly; anda storage unit for supporting a portion of the cable, and the clampbeing positioned intermediate the storage unit and the mold assembly. 7.The assembly of claim 6, further comprising a workbench supporting themold assembly, the clamp, and the cable.
 8. The assembly of claim 7,wherein the workbench further includes a workbench track, wherein thecable is positioned within the workbench track.
 9. The assembly of claim6, wherein the clamp and the storage unit are upstream of the moldassembly.
 10. The assembly of claim 6, wherein the cable extends fromthe mold assembly to the clamp and the storage unit.
 11. An assemblycomprising: a storage unit; a cable containing a plurality of wires andsupported by the storage unit; a workbench including a workbench track,wherein the workbench track rests on the workbench and the cable ispositioned within the workbench track; a clamp removably coupled to thecable; a mold assembly configured to receive the cable and including: afirst upper portion, a second upper portion, and a base; wherein thebase, the first upper portion, and the second upper portion are eachremovably coupled to each other and the configuration of the first upperportion, the second upper portion, and the base creates a channel thatextends along a length of the base to accommodate the cable within thechannel; wherein the base includes a bottom surface, a first topsurface, and a second top surface such that the first top surface is ata greater distance from the bottom surface of the base than the secondtop surface; the first upper portion and the second upper portion eachhaving a bottom surface wherein the bottom surface of the second upperportion is closer to the bottom surface of the base than the bottomsurface of the first upper portion; and a locator plate removablycoupled to the first upper portion, the second upper portion, and thebase; wherein the locator plate includes a plurality of holes eachconfigured to receive one of the plurality of wires of the cable.